Temporal trends, in-hospital outcomes and comorbidity profile in US asthma hospitalizations between 2004 and 2017 (Abstract #146)

Background: Asthma is a prevalent chronic respiratory condition and a common cause for admissions, but contemporary US data on hospitalization rates, comorbidity burden, and outcomes among patients admitted with asthma are limited.

Objectives: To examine annual trends of US asthma hospitalizations, comorbidity profile by patient factors and in-hospital outcomes over 14 years (2004–2017).

Methods: Population based study-using data from the US Nationwide Inpatient Sample (NIS). NIS, sponsored by the Agency for Healthcare Research and Quality (AHRQ), is the largest available all-payer data on inpatient stays from all US states participating in the Healthcare Cost and Utilization Project, covering >97% of the US population. We included hospitalizations with a primary diagnosis of asthma between 2004 and 2017. Outcomes were the number of hospitalizations per 100 000 populations, length of stay, in-hospital ventilation, and costs. Annual changes in patient and admission characteristics were examined. Multivariable regression models were used to identify predictors of in-hospital outcomes over-time. All analyzes were survey-weighted to produce a nationally representative estimate of the entire US population of hospitalized patients.

Results: A total of 3 098 863 (996/100 000 population) asthma hospitalizations were identified between 2004 and 2017. Hospitalizations declined from 89/100 000 in 2004 to 56/100 000 population in 2017, mean (±SD) length of stay remained overall stable (2.71 ± 2.5 days), but median (IQR) inflation-adjusted costs doubled from $8444 (9225) in 2004 to $17 756 (19 434) in 2017. Mean age was 29 (±25) years, 36% White, 27% Black, 57% females, and 40% by Medicaid payer. Common comorbidities in adults were hypertension and diabetes; and in children, obesity, gastroesophageal reflux disease (GERD), anemia. Mental illness prevalence increased by >50% over time. Psychoses (IRR, 1.10; 1.05–1.14; p 
Conclusions: Declining US asthma hospitalizations may reflect improvements in community care. Our findings highlight increasing comorbidity burden and the changing landscape of asthma admissions may inform services redesign to support pre-hospitalization care.